A Thematic Compilation by Avi Sion

Blog posts
: "Logic"

Logic is founded on certain ‘laws of thought’, which were first formulated by Aristotle, an ancient Greek philosopher. We shall describe them separately here, and later consider their collective significance.

Reality and illusion are attributes of phenomena. When we turn our attention to the implicit ‘consciousness’ of these phenomena, we correspondingly regard the consciousness as realistic or unrealistic. The consciousness, as a sort of peculiar relation betwee…

We began our study by presenting the laws of thought — the Laws of Identity, of Contradiction, and of the Excluded Middle — as the foundations of logic. We can see, as we proceed, that these first principles are repeatedly appealed to in reasoning and v…

A very important field of logic is that dealing with paradox, for it provides us with a powerful tool for establishing some of the most fundamental certainties of this science. It allows us to claim for epistemology and ontology the status of true sciences, instead of mere speculative digres…

We have seen that logical propositions of the form ‘if P, then nonP’ (which equals to ‘nonP’) or ‘if nonP, then P’ (which equals to ‘P’), are perfectly legal. They signify that the antecedent is self-contradictory and logically impossible, and that the conseque…

Western philosophical and scientific thought is based on Aristotelian logic, whose founding principles are the three “Laws of Thought”. These can be briefly stated as “A is A” (Identity), “Nothing is both A and non-A” (Non-contradiction) and “Nothing is nei…

Phenomenology may be defined as the study of appearances as such. By an ‘appearance’ is meant any existent which impinges on consciousness, anything cognized, irrespective of any judgment as to whether it be ‘real’ or ‘illusory.’ The evaluation of a particul…

By ‘appearance’ is meant, first of all, anything and everything – but upon reflection, more specifically anything which ‘comes to mind,’ by whatever means. This is not a definition, but an indication. The term appearance is too fundam…

Allied to sameness and difference are the concepts of compatibility or incompatibility, which underlie what Aristotle has called the three ‘laws of thought’ – identity, non-contradiction and exclusion-of-the-middle. How do we apprehend things (percepts, intui…

Logic is usually presented for study as a static description and prescription of forms of proposition and arguments, so that we forget that it is essentially an activity, a psychic act. Even the three Laws of Thought have to be looked at in this perspect…

Many people misunderstand what we logicians mean by ‘contradiction’. The contradictory of a term ‘A’ is its negation, ‘not A’, which refers to anything and everything in the universe other than A, i.e. wherever precisely A is absent in the world. The relat…

The three Laws of Thought must not be construed as some prejudice of Aristotle’s, which some scientific discovery – like the particle-wave duality or the relativity of space-time measurements – could conceivably raise doubt about or displace. Th…

Phenomenology results from a realization that the building blocks of knowledge are appearances. This realization is obtained through a dialectic, comprising thesis, antithesis and synthesis, as follows.

Concepts and theories are hypothetical constructs. They cannot (for the most part) be proven (definitely, once and for all), but only repeatedly confirmed by experience. This is the positive side of adduction, presenting evidence in support of rational con…

Returning to logic – our insight [earlier] into the nature of negation can be construed to have formal consequences. The negative term is now seen to be a radically different kind of term, even though in common discourse it is made to behave like any…

Concerning the uniformity principle, which Hume denies, it is admittedly an idea difficult to uphold, in the sense that we cannot readily define uniformity or make a generality of it. We might speak of repetition, of two or more particular things …

Discussion of the laws of thought inevitably arrives at the question: are these ontological or epistemological laws, or both; and if both in what sequence? Furthermore, what is their own ontological status – i.e. where do they ‘reside’, as i…